AD 90-15-10

90-15-10 LOCKHEED AERONAUTICAL SYSTEMS COMPANY: Amendment 39-6662. Docket No. 90-NM-115-AD. Applicability: Model L-1011 series airplanes, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent structural failure of the aft and mid fuselage eight-inch diameter duct compensators, accomplish the following:

A. Within the next 300 flight hours after the effective date of this AD, verify that the part numbers of the aft and mid fuselage 8-inch diameter bleed air duct compensators coincide with the part numbers listed in Table I of the Accomplishment Instructions, Lockheed Service Bulletin 093-36-064, dated May 29, 1990.

1. If the part numbers coincide with the part numbers listed in Table I, no further actions are required.

2. If any compensator is found without coinciding part numbers, prior to further flight, conduct a thorough visual inspection of the fillet weld on the barrel assembly for cracks.a. If there is no evidence of cracking in the weld area, the compensator may remain in service and the visual inspection must be performed at intervals not to exceed 150 flight hours.

b. If there is evidence of cracking during any inspection, prior to further flight, replace the compensator with one having a part number listed in Table I.

B. Replacement of any aft or mid fuselage 8-inch diameter bleed air duct compensator with one having a part number listed in Table I of the Accomplishment Instructions of Lockheed Service Bulletin 093-36-064, dated May 29, 1990, constitutes terminating action for the repetitive inspections required by paragraph A.2., above, for that compensator.

C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Los Angeles ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Los Angeles ACO.

D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service information from the manufacturer may obtain copies upon request to Lockheed Aeronautical Systems Company, P.O. Box 551, Burbank, California 91520, Attention: Commercial Order Administration, Dept 65-33, U-33, B-1. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California.

This amendment (39-6662, AD 90-15-10) becomes effective July 31, 1990.